TerraSAR-X is the Synthetic Aperture Radar (SAR) German satellite which provides a high diversity of information
due to its high-resolution. TerraSAR-X acquires daily a volume of up to 100 GB of high complexity,
multi-mode SAR images, i.e. SpotLight, StripMap, and ScanSAR data, with dual or quad-polarization, and with
different look angles. The high and multiple resolutions of the instrument (1m, 3m or 10m) open perspectives
for new applications, that were not possible with past lower resolution sensors (20-30m). Mainly the 1m and
3m modes we expect to support a broad range of new applications related to human activities with relevant
structures and objects at the 1m scale. Thus, among the most interesting scenes are: urban, industrial, and
rural data. In addition, the global coverage and the relatively frequent repeat pass will definitely help to acquire
extremely relevant data sets. To analyze the available TerrrSAR-X data we rely on model based methods for
feature extraction and despeckling.
The image information content is extracted using model-based methods based on Gauss Markov Random
Field (GMRF) and Bayesian inference approach. This approach enhances the local adaptation by using a prior
model, which learns the image structure and enables to estimate the local description of the structures, acting
as primitive feature extraction method. However, the GMRF model-based method uses as input parameters the
Model Order (MO) and the size of Estimation Window (EW). The appropriated selection of these parameters
allows us to improve the classification and indexing results due to the number of well separated classes could be
determined by them. Our belief is that the selection of the MO depends on the kind of information that the
image contains, explaining how well the model can recognize complex structures as objects, and according to the
size of EW the accuracy of the estimation is determined.
In the following, we present an evaluation of the impact of the model order selection and the estimation
windows size using TerraSAR-X data. We determine how many classes can be indexed depending on the Model
Order and Estimation Window. The experimental results shows a good choice is model order 3 and 4, and
estimation window with radius 15 × 15 pixels size.